Improvement, Planting & Mulching
Good soil preparation and proper planting are keys to healthy plants and efficient use of water in the garden. Deep cultivation and the addition of compost or other organic materials enhance the soil's ability to absorb and store rainfall or irrigation water for later plant use. Good planting practices allow plants to develop healthy, wide spreading roots which draw water from a large area. These practices contribute to a healthy garden which resists drought and thrives with minimal maintenance and watering.
The Soil Reservoir
Soil is a reservoir that stores moisture and nutrients needed by plants to grow well. Plant roots are the pipes that transfer water and nutrients from the soil to plant leaves.
How well roots do their job depends on soil quality. In soils that are loose and rich in organic material, roots spread freely and can pull water and nutrients from a large area. Water is able to enter loose soils easily, and is stored in organic matter until plants need it.
Poor and compacted soils inhibit roots from spreading to reach nutrients and water. Water runs off compacted soils rather than entering the soil. Plants grown in poor soils can be stunted, and are susceptible to damage from disease, insects and drought.
What Kind of Soil Do You Have?
The only way to find out how well your soil is providing for plant roots is to dig in and check. Dig a one foot deep hole and remove a slice of soil from the side. How does it look and feel? Not compacted layers.
Clay & Silt
Clay and silt soils are made of very small particles. They feel slick and sticky when wet. Clay and silt hold moisture well, but resist water infiltration, especially when they are dry. Often puddles form on clay or silt soils, and they easily become compacted.
Loam soil is a mix of sand, silt or clay, and organic matter. Loam soils are loose and look rich. When squeezed in your fist, moist loam will form a ball which crumbles when poked with a finger. Loam soils normally absorb water and store moisture well. Loam soils can be sandy or clay based, and will vary in moisture absorption and retention accordingly.
Sandy soils contain large particles which are visible to the unaided eye, and are usually light in color. Sand feels coarse when wet or dry, and will not form a ball when squeezed in your fist. Sandy soils stay loose and allow moisture to penetrate easily, but do not retain it for long term us.
Few gardens start with the "rich sandy loam" that gardening books recommend for planting. The soil improvement and planting practices outlined below can help plant roots do better in any soil.
Break Up Compact Soil
Soils that are compacted inhibit drainage and root growth. Break it up using a shovel, pick or rototiller. For maximum root spread, cultivate new garden and turf areas one foot deep, not just where individual shrubs and trees are to be placed. Break through compacted layers so roots can penetrate into looser soil below.